MoguBlog through 6.2 XML External Entity Injection in the Unauthenticated WeChat Callback Endpoint

MoguBlog through 6.2 contains an XML external entity injection vulnerability in the WeChat callback handler at POST /wechat/wechatCheck. The WechatRestApi.index() method passes the raw request body to SignUtil.xmlToMap(), which uses an unhardened dom4j SAXReader without DTD or external-entity restrictions. Unauthenticated remote attackers can submit DOCTYPE declarations with external parameter entities to read arbitrary local files or trigger outbound HTTP requests, with resolved entities reflected in error responses.